Well, it looks like Ed has given me exactly what I was asking for! This switch would be absolutely perfect for the intended application...but the customer would never allow it on the front door of his business. Close, but no cigar.
I haven't gotten into a wholesaler yet to ask about one-shot relays yet, hopefully tomorrow morning.
Trumpy...what I meant about the door being open was just the amount of time it would take for the door to close itself after being opened. The main reason I don't want to use a n.o. switch in this situation is that there are actually two doors to this business, and two chime kits. The front door is set to chime once when a customer enters (ding), and the back door is set to chime twice (ding-dong). With a n.o. reed switch at the back door the coil would energize when the door opened, sending the plunger into the first chime. (ding) But now the coil remains energized until the door closes and the reed switch contacts open, de-energizing the coil, allowing the plunger to be pulled up by spring pressure and hit the second chime. (dong) The trouble is that when either door opens like this you would only hear the ding sound...and if it's the back door that opened you wouldn't know it until the door were once again completely closed...kinda defeating the purpose of having two chime kits to differentiate which door is being opened.
I wish I'd have thought about this before recommending the idea to the customer! Oh well, hopefully I can find a relay that will give the coil a quick jolt.
Fretwell...there's nothing electronic about these chimes...two coils, each with a spring loaded plunger running through it. energize a coil and force its plunger down into a metal bar. de-energize coil and the spring returns plunger to top...one plunger hits a stop bumper, the other hits a second metal bar. pretty simple stuff.
Thanks again everyone.
Shawn.
